This section provides information helpful in understanding the invention but that is not necessarily prior art.
Composite materials having reinforcement or filler materials dispersed in a polymeric matrix are known to exhibit mechanical properties such as stiffness, strength and toughness, which are superior to the polymer in the polymeric matrix alone. These composite materials may be used in a variety of products and as building materials due to their high strength, durability and the ability to easily manufacture and machine such composites into a variety of shapes and designs. In particular, carbon fiber composites are especially desirable because of their high strength-to-weight ratio. Thus, carbon fiber composites may be incorporated into various products including structural and design components of vehicles and aircrafts.
However, carbon fiber composites are susceptible to damage, which may be caused by various factors (e.g., mechanical, chemical, thermal, etc.). This damage may lead to microcracks within the carbon fiber composite, which can be difficult to detect and repair and over time can potentially result in premature failure of the carbon fiber composite material. Thus, there is a need for carbon fiber composites, which are able to self-heal or self-repair following damaging events to extend the life of carbon fiber composites.
One approach, known as extrinsic self-healing, is to provide a microencapsulated healing agent within the carbon fiber composite material, which upon fracture, is released and rebonds/repairs the cracks in the composite material. However, this approach is limited by the amount of healing agent included in the carbon fiber composite material because once the healing agent is exhausted, no further damage can be repaired. Another approach, known as intrinsic self-healing, incorporates self-healing functional groups into the polymer chains to make the polymeric matrix itself self-healable, where the self-healing groups possess a latent self-healing functionality that is activated by damage or by an external stimulus. However, many self-healable polymers may show inferior mechanical and physical properties resulting in a carbon fiber composite with reduced strength and stability. Thus, there is a need for further self-healing composite materials with increased strength and stability.